1. Field of the Invention
The present invention relates to an incising device for use with endoscope, to be inserted into a patient's body through an endoscope and subject an organic tissue, such as a mucous membrane, to energy incision.
2. Description of the Related Art
Conventionally described in Jpn. UM Appln. KOKAI Publication No. 61-191012, for example, is a high-frequency instrument to be inserted into the body cavity through an endoscope and excise a mucosal part in a wide range in the body cavity. This high-frequency instrument comprises an electrically conductive sheath, a tip member attached to the distal end portion of the sheath, and a control wire passed through the sheath. The sheath can be passed through a channel of the endoscope. The control wire has, on its distal end portion, a knife that can project and recede from the tip member.
The knife is a rod-shaped member, which is formed of a single wire having a pointed end, or a member in the form of a thin sheet. As the knife is supplied with high-frequency current and heated, it can subject a tissue to high-frequency incision. Alternatively, a wire may be used to subject a region around an affected part of a mucous membrane in a wide range to high-frequency incision. In this case, a submucosa is exfoliated to be excised by means of this high-frequency incision tool.
As is generally known, a high-frequency snare is used endoscopically to excise polyps or mucous membranes. This high-frequency snare comprises an electrically conductive sheath, an incision wire passed through the sheath, and a slider. The sheath can be passed through a channel of an endoscope. The slider is slidably mounted on the proximal portion of the incision wire.
As the slider is advanced by means of a handle, in this high-frequency snare, the incision wire projects from the distal end of the sheath and spreads in a loop, undergoing restorative deformation. Originally, in this high-frequency snare, the incision wire is spread in a loop. In this state, the incision wire is hooked on an affected part, and the slider is retreated. The incision wire is drawn into the sheath to a degree such that the affected part touches the sheath, and the affected part is bound.
In excising a mucous membrane in a wide range, according to an alternative method of use of the high-frequency snare, the incision wire is projected about 1 mm from the sheath as it is supplied with high-frequency current. By doing this, the wire can be heated to subject a tissue to high-frequency incision. Thus, the incision wire can be used to mark the region around the affected mucosal part in a wider range, effect high-frequency incision, or exfoliate a submucosa.